Various applications exist where the illumination of a target object or being is required for its observation to provide easier detection, classification, recognition, identification or tracking of the target. Examples for such applications include perimeter security and surveillance, police search operation, search and rescue, firefighting, industrial inspection, maintenance and road safety. Such illumination of a target is generally required, for example, when there is a need to observe or locate the target in adverse conditions such as during night, in a cluttered environment or in the presence of smoke, fog or dust.
Some sensors exist which provide the capability to detect targets in night conditions. An example of such sensors includes infrared sensors which detect the heat emitted by the target instead of visible light reflected by the object. However, infrared sensors do not allow for direct observation by human, observation by human via visible-waveband observation devices or observation by automatic observation devices that operate in other wavebands than infrared.